It is a willingness to face not only your opponents, but also your own fears. That reason, fear, as ESPN indirectly points out, is the most difficult reason than any other that boxing is the hardest sport. Nothing drains you and creates fatigue like fear.
Does boxing build muscle?
The answer is yes! Boxing is a great full-body exercise that can help you build muscle in your legs, hips, core, arms, chest and shoulders. It can also help with your strength, speed, hand-eye coordination, agility, endurance, and strength.
Which is better for self defense boxing or karate?
The main area that gives karate an edge over boxers is the volume of techniques they learn. This may interest you : What martial art does Batman use?. While boxers are limited to punches and punches, karateka learns a variety of kicks, throws, and take-down maneuvers in addition to hand techniques.